300ex jetting

[pimpin330ex]

hey i have a 2001 300ex with a 400ex carb that im having trouble gettin to run right. as of right now it has a stock 400ex jet in it with the mixture screw 2 and a half turns out. and its bogging down very bad when throttles stabbed also back fires a little when throttles let off. the mods my engine has is 1 mm over sized valves port and polished head 11:1 compression wiesco piston a white bros pipe k and n filter with outer wears pre filter any sugestioms on what to do would be great thanks

[bwamos]

With my setup I'm running a 160-165 main (I beleive, been an while since ive torn it open.)

Is it bogging or loading up?

If it's trully bogging then you are probably lean. (which would be my guess)

I have to put a 42 pilot in mine also to stop the backfire on decel.


Stock 400ex is a 142 main (correct?) I'd grab a 150 and a 155 from the dealership and do some testing.

[pimpin330ex]

ok i will try that alos whats your needle clip at and how far out is your mixture screw?

[Kickstarts-suck]

i had 145 in mine

with 12:1 compression .020
400ex carb
uni clamp on
stock exhaust